Pentazocine is a member of benzomorphan class that is chemically similar to morphine and used as a non-narcotic analgesic. The action of pentazocine is a potent analgesic with both agonist and antagonist at opioid receptors. Pentazocine is a controlled drug and is prescribed parenterally for moderate to severe acute post-operative pain in some countries. In comparison to morphine or pethidine, the duration of action of pentazocine is slightly shorter and so, known as a non addicting analgesic, when it had been first presented. A 53-year-old healthcare professional; a Middle Eastern male who was referred to our addiction clinic in 2013 with the complaints related to excessive use of some analgesics including pentazocine in parenteral form. He has been on duty in a health service in the First Persian Gulf War (early 1990) and he first met pentazocine there. He had 6 ampules of analgesics containing pentazocine in his service and used 4 of them for patients suffering from traumatic injuries in the war and used 2 of them for himself. He has been diagnosed to have migraine 30 years ago and he explains the reason of abuse as he was suffering from migraine during the war. Then he began to abuse pentazocine up to 20 ampules per day for more than 15 years. He has tried to give up more than 6 times but a duration of 15 days was the longest period that he was abstinent without any treatment. He was suffering from musculoskeletal pain, diarrhea, some other complaints associated with gastrointestinal tract and also insomnia and anhedonia during the first week of withdrawal. He said he was using pentazocine to avoid these unpleasant withdrawal symptoms and to stay awake. He has guiltiness thoughts about his abuse pattern and was depressive in mood. He was using 10 pentazocine ampules corresponding to 30 mg in total intramuscularly in his left inguinal region for more than 6 months before his admission to our clinic. He has a wound in his left inguinal region, containing necrotic and infectious tissue and he has been dressing this wound by himself for months. Patient was hospitalized in our inpatient clinic with the diagnosis of opioid addiction and necrotic wound due to repetitive intramuscular pentazocine injection. Patient underwent our 12-steps therapy for addiction and received Quetiapine 200 mg, Bupropion 150 mg and Naltrexone 50 mg after detoxification treatment. He has been under follow up at our outpatient clinic for 5 months and he is still abstinent, functional in his occupation and social domains. After some surgical operations he underwent in Turkey, his wound healed too. Although the efficacy of pentazocine is comparable to morphine, its side effects are still considerable, particularly its potential of abuse. Repeated intramuscular injections of pentazocine may cause soft tissue induration, fibrosis or ulceration, hyperpigmentation and a myopathy (more often associated with drug abuse rather than therapeutic use). Although pentazocine is known to be abused, particularly by the patients who have chronic pain, Since many years it has already been widely used in some poorly resourced countries.